U.S. civil rights leader Jesse Jackson said Monday he was ready to meet North Korea’s leader to free an imprisoned American and reduce ill-will between the two countries.

U.S. officials have said that Jackson volunteered to travel to Pyongyang after the totalitarian state abruptly canceled the visit of a U.S. envoy, Robert King, who aimed to free Korean-American tour operator Kenneth Bae.

Jackson said in a televised interview with CNN that he had put “high hopes” in King, but after the trip was called off, wrote a letter to North Korean leader Kim Jong-Un.

Jackson said he told Kim he would “like to meet with him face-to-face to seek to work out some mutual respect, some recognizing each other’s sovereignty, each other’s will to peace.”

North Korea, which technically remains at war with US-ally South Korea, has defiantly pursued nuclear weapons in what it says is its effort to counter hostility from the United States.

Bae, described by a North Korean court as a militant Christian evangelist, was arrested in November 2012 and later sentenced to 15 years of hard labor on charges of seeking to topple the government.

Terri Chung, the prisoner’s sister, said that the family has been in contact with Jackson for several weeks and has been “touched by his warmth, generosity of spirit and his investment in bringing Kenneth home.”

“Regardless of the outcome, we are deeply grateful to Reverend Jackson for his proactive pursuits of Kenneth’s freedom,” she said in a statement.

Chung said that the family was “alarmed” at news that Bae — said to suffer from back pain and other medical conditions — had been sent back to a labor camp.

“We remain gravely concerned that the stress Kenneth endures at the labor camp will be too much for him. We do not know whether his body will be able to withstand the strains of hard labor, eight hours a day, six days a week,” she said.

Jackson, a longtime activist who campaigned with the late civil-rights leader Martin Luther King, has frequently sought to assist in international crises. He secured Iraqi leader Saddam Hussein’s release of U.S. and British citizens before the 1991 Gulf War and later met Yugoslav president Slobodan Milosevic to bring home three U.S. prisoners of war.